A National Study
of School Effectiveness for Language Minority Students Long-Term
Academic Achievement

Final Report

Executive Summary

Principal Investigators:

Wayne P. Thomas

Virginia P. Collier

Purpose. Our research from 1985 to 2001 has focused
on analyzing the great variety of education services provided for language
minority (LM) students in U.S. public schools and the resulting long-term
academic achievement of these students. This five-year research study
(1996-2001) is our most recent overview of the types of U.S. school programs
provided for these linguistically and culturally diverse students, especially
focusing on English language learners (ELLs/LEPs) academic achievement
in Grades K-12. This study includes qualitative and quantitative research
findings from five urban and rural research sites in the northeast, northwest,
south-central, and southeast U.S. It is designed to answer urgent policy
questions of interest to the federal and state governments of the United
States, since this demographic group is projected to be 40 percent of
the school-age population by the 2030s and most U.S. schools are currently
under-educating this student group. Overall, this research provides whole
school district views of policy decision-making that is data-driven regarding
designing, implementing, evaluating, and reforming the education of LM
students.

Analyses. As principal investigators, we established
a collaborative research agreement with each school district that chose
to participate, to follow every LM student who entered the school district
for every year of his/her attendance in that school district, by each
program type attended including the mainstream, and by cohorts of similar
student background (e.g. socioeconomic status, primary language [L1] and
second language [L2] proficiency upon entry, prior schooling). Measures
of student achievement were those administered by the school district,
including standardized test scores. We reported generalizations across
school districts based on group performance on standardized measures,
in normal curve equivalents (NCEsequal-interval percentiles). Quantitative
analyses proceeded through five research stages (presented in detail in
report), each stage followed by collaborative interpretation of the results
with school district staff. Qualitative analyses from interviews, school
visits, surveys, and source documents, included historical demographic
patterns of linguistically diverse groups of each U.S. region, the sociolinguistic
and social context for the school programs, and specific implementation
characteristics of each program type, including a case study of one school
innovation.

Research sites, student samples, and program types
analyzed. By written agreement, the school districts participating
in each of our studies are promised anonymity until they choose to self-identify.
For this study, four sites decided to self-identifyMadawaska School
Department and School Administrative District #24, both located in northern
Maine; Houston Independent School District in Texas; and Grant Community
School in Salem, Oregon. The total number of student records collected
in the five school districts featured in this report was 210,054. (One
student record includes all the school district records for one student
collected during one school year, such as student background characteristics,
the grade level and school program(s) that student attended, and academic
achievement measures administered to that student during the school year.)
Over 80 primary languages were represented in the student samples, but
the data analyses in three of the five research sites focused on Spanish
speakers, the largest language group in the U.S. (75 percent of the U.S.
LM school-age population). The student samples included newly arriving
immigrants as well as ethnolinguistic groups of French cultural and linguistic
roots in the northeast and students of Spanish-speaking heritage in the
south-central U.S. The analyses focused on student outcomes from eight
major different program types for LM students90-10 two-way bilingual
immersion (or dual language), 50-50 two-way bilingual immersion, 90-10
one-way developmental bilingual education, 50-50 one-way developmental
bilingual education, 90-10 transitional bilingual education, 50-50 transitional
bilingual education, English as a Second Language (ESL) taught through
academic content, and the English mainstream.

FINDINGS: Qualitative findings are presented in
the full report. Major findings from the quantitative analyses that are
statistically and practically significant for decision-making are presented
below. For decision-making purposes, a 4 NCE difference between groups
is considered a small but significant difference (0.2 of a national standard
deviation [s.d.]), 5 NCEs an actionable significant difference (0.25 of
a national s.d.), 6 NCEs a moderate significant difference (0.3 of a national
s.d.), and 10 NCEs a very large significant difference (0.5 of a national
s.d.).

ENGLISH ACHIEVEMENT FINDINGS: Focusing first on
program comparisons, we summarize English language learners
long-termachievement on nationally standardized tests (ITBS,
CTBS, Stanford 9, Terra Nova) in English Total Reading (the subtest
measuring academic problem-solving across the curriculummath, science,
social studies, literature), for students who entered the U.S. school
district with little or no proficiency in English in Grades K-1, and following
them to the highest grade level reached by the program to date:

English language learners immersed in the English mainstream because
their parents refused bilingual/ESL services showed large decreases
in reading and math achievement by Grade 5, equivalent to almost 3/4
of a standard deviation (15 NCEs), when compared to students who received
bilingual/ESL services. The largest number of dropouts came from this
group, and those remaining finished 11th grade at the 25th
NCE (12th percentile) on the standardized reading test. (pp.
113-114, 122-124, Figures C-1, C-2, Tables C-1, C-2, C-10, C-11)

When ESL content classes were provided for 2-3 years and followed
by immersion in the English mainstream, ELL graduates ranged from the
31st to the 40th NCE with a median of the 34th
NCE (23rd percentile) by the end of their high school years.
(pp. 112-114, 126-127, 241-256, Figures C-1, C-2, E-1, E-6, E-7, E-8,
E-9, E-14, Tables C-1, C-2, E-1, E-6, E-7, E-8, E-9, E-14)

50-50 Transitional bilingual education students who were former ELLs,
provided with 50 percent instruction in English and 50 percent instruction
in Spanish for 3-4 years, followed by immersion in the English mainstream,
reached the 47th NCE (45th percentile) by the
end of 11th grade. (pp. 112-114, 126-127, Figures C-1, C-2,
Tables C-1, C-2)

90-10 Transitional bilingual education students who were former ELLs
reached the 40th NCE (32nd percentile) by the
end of 5th grade. (In 90-10 TBE, for Grades PK-2, 90 percent
of instruction is in the minority language, gradually increasing English
instruction until by Grade 5, all instruction is in the English mainstream
for the remainder of schooling.) (pp. 119-122, Figure C-8, Table C-7)

50-50 One-way developmental bilingual education students who were
former ELLs reached the 62nd NCE (72nd percentile)
after 4 years of bilingual schooling in two high-achieving school districts,
outperforming their comparison ELL group schooled all in English by
15 NCEs (almost 3/4 of a national standard deviationa very large
significant difference). By 7th grade, these bilingually
schooled former ELLs were still above grade level at the 56th NCE (61st
percentile). (One-way is one language group being schooled through two
languages.) (pp. 48-52, 58, Figures A-1, A-3, Tables A-5, A-6)

90-10 One-way developmental bilingual education students who were
former ELLs reached the 41st NCE (34th percentile)
by the end of 5th grade. (90-10 means that for Grades PK-2,
90 percent of instruction is in the minority language, gradually increasing
English instruction to 50 percent by Grade 5, and a DBE program continues
both languages in secondary school.) (pp. 119-122, Figure C-8, Table
C-7)

50-50 Two-way bilingual immersion students who were former ELLs attending
a high-poverty, high-mobility school: 58 percent met or exceeded Oregon
state standards in English reading by the end of 3rd and
5th grades. (Two-way is two language groups receiving integrated
schooling through their two languages; 50-50 is 50 percent instruction
in English and 50 percent in the minority language.) (pp. 201-204, Figures
D-4, D-6, Table D-18)

SPANISH ACHIEVEMENT FINDINGS: A goal of one-way
and two-way bilingual education is to graduate students who are fully
academically proficient in both languages of instruction, to prepare these
students for the workplace of the 21st century. We summarize
native-Spanish-speakers long-term achievement on nationally
standardized tests (Aprenda 2, SABE) in Spanish Total Reading (the
subtest measuring academic problem-solving across the curriculummath,
science, social studies, literature), following them to the highest grade
level reached by the program to date:

In 50-50 Two-way bilingual immersion, Spanish-speaking immigrants
after 1-2 years of U.S. schooling achieved at a median of the 62nd
NCE (71st percentile) in Grades 3-6. These immigrants arrived
on or above grade level and maintained above grade level performance
in Spanish in the succeeding two years. (pp. 199-200, Figure D-2, Tables
D-5, D-6)

In 90-10 Transitional bilingual education classes, native-Spanish
speakers reached the 56th to 60th NCE (61st
to 68th percentile) for Grades 1-4, and after moving into
all-English instruction in Grade 5, they tested at the 51st
NCE, still on grade level in Spanish reading achievement. (pp.117-119,
Figure C-5, Table C-4)

We chose the reading subtest of the standardized tests (results presented
above) as the "ultimate" measure of attainment, because LM
students reading scores were consistently the lowest among the
subjects, and this is the measure that most closely correlates with
the standardized tests required for admission to post-secondary education.
Generally, LM students achieved 5-10 NCEs higher in English language
arts, math, science, social studies, and writing. (pp. 46-53, 111-114,
119-122, 241-256, Figures A-4, A-5, C-9, C-10, E-1 to E-14 and accompanying
tables)

Socioeconomic status (SES) typically influenced from 3-6% of LM students
reading achievement as measured by standardized tests, for both enrichment
dual language programs and ESL content programs. In selected circumstances
(e.g., oral proficiency of Spanish speakers learning English) the effect
of SES explains as much as 11-12% of achievement. However, the effect
of number of years of program participation on reading achievement varied
with the program type. For one-way and two-way dual language programs,
up to five years of program participation accounted for 6-9% of ELLs
reading achievement on standardized tests. For Spanish speakers learning
English, 20% of oral proficiency was attributable to program exposure
while program exposure accounted for 15% of oral proficiency for English
speakers learning Spanish. In the case of the ESL Content program, years
of schooling accounted for less than 2% of end-of-school reading achievement
as measured by standardized tests. Thus, a strong dual language program
can "reverse" the negative effects of SES more than a well-implemented
ESL Content program by raising reading achievement to a greater degree.
(pp. 56-57, 204-206, 256-258, Tables A-18, D-20, E-16 to E-18)

The One-way developmental bilingual education program in Northern
Maine influenced 8.5% of former ELLs eventual reading achievement,
exceeding the effects of low socioeconomic status at less than 4%. The
Two-way bilingual immersion program at Grant Community School exerted
a powerful and significant effect on Spanish-speaking students
scores on oral English development and influenced about 6 percent of
their standardized reading scores as assessed in English, while SES
accounted for about 4%. In this high-poverty school, SES alone accounted
for 14 percent of the observed achievement variance overall. Thus, the
schools dual language program is reducing the negative effects
of SES by significant amounts for Spanish speakers learning English
and taking the statewide assessment in English. (pp. 56-57, 204-206,
256-258, Tables A-18, D-20, E-16 to E-18)

Number of years of primary language schooling, either in home country
or in host country, had more influence than socioeconomic status when
the number of years of schooling was 4 or more years. In addition, the
L2 academic achievement of older immigrant arrivals with strong grade-level
schooling completed in L1 in the home country was less influenced by
low socioeconomic status and more dependent on number of years completed.
Likewise, students of low socioeconomic status who were born in the
U.S. or arrived at a very young age achieved at high levels in L2 when
grade-level schooling was provided in both L1 and L2 in the U.S. (pp.
257-258, Figures C-1, E-6, E-7, Tables C-1, E-6, E-7, E-17, E-18)

When immigrants were schooled all in English in the U.S., students
who received 4-5 years of L1 schooling in home country (arriving at
ages 10-12) scored 6 NCEs higher in English reading in 11th
grade than those who received 1-3 years of home country schooling (arriving
at ages 7-9). (pp. 248-251, Figures E-6, E-7, Tables E-6, E-7)

Immigrants with interrupted schooling in home country achieved significantly
below grade level, when provided instruction only in English. Those
one year below grade level on arrival were at the 29th NCE
(16th percentile) on the English reading test by 11th
grade, those two years below grade level on arrival at the 26th
NCE (13th percentile), those three years behind at the 20th
NCE (8th percentile), and those four years behind at the
19th NCE (7th percentile). (pp. 251-253, Figure
E-8, Table E-8)

Gender differences among Hispanic students were found to be significant
in only two subject areasmath and science. Hispanic males outperformed
Hispanic females by 4 NCEs in math and 6 NCEs in science on the 11th
grade tests in English. (p. 256, Figure E-14, Table E-14)

MAJOR POLICY IMPLICATIONS:

Enrichment 90-10 and 50-50 one-way and two-way developmental bilingual
education (DBE) programs (or dual language, bilingual immersion) are
the only programs we have found to date that assist students to fully
reach the 50th percentile in both L1 and L2 in all subjects
and to maintain that level of high achievement, or reach even higher
levels through the end of schooling. The fewest dropouts come from these
programs.

Parents who refuse bilingual/ESL services for their children should
be informed that their childrens long-term academic achievement
will probably be much lower as a result, and they should be strongly
counseled against refusing bilingual/ESL services when their child is
eligible. The research findings of this study indicate that ESL or bilingual
services, as required by Lau v. Nichols, raise students
achievement levels by significant amounts.

When English language learners (ELLs) initially attend segregated,
remedial programs, these students do not close the achievement gap after
reclassification and placement in the English mainstream. Instead, they
maintain or widen the gap in later years. Therefore, their average achievement
NCE at reclassification should be as high as possible, since this is
likely to be their highest achievement level that they reach during
their school years. Ideally, instructional gains are best accomplished
in an enrichment (not a remedial) program.

Students with no proficiency in English must NOT be placed in short-term
programs of only 1-3 years. In this study and all other research studies
following ELLs long term, the minimum length of time it takes to reach
grade-level performance in second language (L2) is 4 years. Furthermore,
only ELLs with at least 4 years of primary language schooling reach
grade-level performance in L2 in 4 years. Students with no primary language
schooling (either in home country or host country) are not able to reach
grade-level performance in L2.

The strongest predictor of L2 student achievement is amount of formal
L1 schooling. The more L1 grade-level schooling, the higher L2 achievement.

Bilingually schooled students outperform comparable monolingually
schooled students in academic achievement in all subjects, after 4-7
years of dual language schooling.

Students who receive at least 4-5 years of grade-level L1 schooling
in home country before they emigrate to the U.S. typically reach the
34th NCE (23rd percentile) by 11th
grade when schooled all in English in the U.S. in an ESL Content program,
and then the mainstream. These students are on grade level when they
arrive, but it takes them several years to acquire enough English to
do grade-level work, which is equivalent to interrupting their schooling
for 1 or 2 years. Then they have to make more gains than the average
native-English speaker makes every year for several years in a row to
eventually catch up to grade level, a very difficult task to accomplish
within the remaining years of K-12 schooling.

The highest quality ESL Content programs close about half of the total
achievement gap.

When ELLs initially exit into the English mainstream, those schooled
all in English outperform those schooled bilingually when tested in
English. But the bilingually schooled students reach the same levels
of achievement as those schooled all in English by the middle school
years, and during the high school years the bilingually schooled students
outperform the monolingually schooled students (see Figure C-2).

Students who receive at least 5-6 years of dual language schooling
in the U.S. reach the 50th NCE/percentile in L2 by 5th
or 6th grade and maintain that level of performance, because
they have not lost any years of schooling. All students who are raised
in a dual language environment need at least 4 years of schooling in
L1 and 4 years of schooling in L2 to achieve on grade level in either
of the two languages. Providing bilingual schooling in the U.S. meets
both needs simultaneously, leading to high academic achievement in the
long term.

Bilingual/ESL Content programs must be effective (at least 3-4 NCE
gains per year more than mainstream students are gaining per year),
well implemented, not segregated, and sustained long enough (5-6 years)
for the typical 25 NCE achievement gap between ELLs and native-English
speakers to be closed. Even the most effective programs can only close
half of the achievement gap in 2-3 years, the typical length of remedial
ELL programs.

An enrichment bilingual/ESL program must meet students developmental
needs: linguistic (L1-L2), academic, cognitive, emotional, social, physical.
Schools need to create a natural learning environment in school, with
lots of natural, rich language (L1, L2), both oral and written, used
by students and teachers; meaningful, real world problem-solving;
all students working together; media-rich learning (video, computers,
print); challenging thematic units that get and hold students
interest; and using students bilingual-bicultural knowledge to
bridge to new knowledge across the curriculum.